Lord Burghley had replaced three men, who had been paid to clean his water from weeds, with four swans who work free of charge.
“One of the communications of the Marquis of Exeter to the editor of a periodical publication, which we lately noticed, is a discovery that swans will keep water perfectly free from weeds. At his Lordship’s seat at Burghley, a piece of water, which used to employ three men for six months in a year to keep it tolerably clean, is now kept completely so by two pair of swans.”
Stamford Mercury, 11th November 1803.